s = "我的中国SSwws2221#$#你好要要在"
print(max(s))
print()
for i in s:
    print(i)

print()


s1 = 'Welcome to Python'
s2 = s1
s3 = 'Welcome to Python'
s4 = 'to'

print(s1==s2)
print(s2.count('o'))
print(id(s1)==id(s2))
print(id(s1)==id(s3))
print(s1<=s4)
print(s2>=s4)
print(s1!=s4)
print(s1.upper())
print(s1.find(s4))
print(s1[4])
print(s1[4:8])
print(4*s4)
print(len(s1))
print(max(s1))
print(min(s1))
print(s1[-4])
print(s1.lower())
print(s1.rfind('o'))
print(s1.startswith(('o')))
print(s1.endswith('o'))
print(s1+s1)
